Partitioned surgical instrument

ABSTRACT

A surgical instrument a reusable component and a disposable component selectively separable from and engagable with the reusable component. The disposable component includes an end effector and a mechanical actuator operable to induce mechanical movement of the end effector. The reusable component is configured for providing electrosurgical energy to the disposable component when engaged with the disposable component. A physical mating feature is configured to maintain engagement between the reusable and disposable components when the reusable and disposable components are engaged, and an electrical mating feature is configured to transmit electrical energy between the disposable and reusable components when the disposable and reusable components are engaged. All mechanical motion resulting from operation of the mechanical actuator may be contained within the disposable component.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of U.S. ProvisionalApplication Ser. No. 61/589,549 entitled “PARTITIONED SURGICALINSTRUMENT” filed Jan. 23, 2012 by Christopher A. Deborski et al., theentire contents of which being incorporated by reference herein.

BACKGROUND

1. Technical Field

The present disclosure relates generally the field of reposable orreusable surgical instruments. In particular, the disclosure relates toinstruments having separable and replaceable components to provideclean, sterile or refurbished surfaces in each instance of use.

2. Background of Related Art

Instruments such as electrosurgical forceps are commonly used in openand endoscopic surgical procedures to coagulate, cauterize and sealtissue. Such forceps typically include a pair of jaw members that can becontrolled by a surgeon to grasp targeted tissue, such as, e.g., a bloodvessel. The jaw members may be approximated to apply a mechanicalclamping force to the tissue, and are associated with at least oneelectrode surface to permit the delivery of electrosurgical energy tothe tissue. The combination of the mechanical clamping force and theelectrosurgical energy has been demonstrated to join adjacent layers oftissue captured between the jaw members. When the adjacent layers oftissue include the walls of a blood vessel, sealing the tissue mayresult in hemostasis. Thereafter, the sealed tissue may be transected byadvancing a knife through the jaws. A detailed description of the use ofan electrosurgical forceps may be found in U.S. Pat. No. 7,255,697 toDycus et al.

In use, various tissue-contacting components of an electrosurgicalforceps tend to become contaminated or degraded. For example, electrodesmay become contaminated as portions of the treated tissue adhere to thetissue-contacting surfaces of the electrodes. Also, a knife blade maybecome dull and less effective in transecting sealed tissue afterrepeated use, even in a single surgical procedure. In order to provideclean electrodes and a sharp knife for a particular surgical procedure,a brand new instrument is often used. Once the procedure is complete,the used instrument is discarded.

Instruments that are reposable, or reusable for multiple procedures,reduce the instrumentation costs per procedure. Providing a reusableelectrosurgical forceps, however, presents various challenges. Forexample, the complexity of an electrosurgical forceps tends to result infairly labor intensive cleaning procedures to prepare the forceps forsubsequent use. Improper cleaning may result in dangerous contaminationbeing introduced to the surgical site. Also, some reusable forceps haveremovable and replaceable components to provide clean surfaces for eachuse. Many of these instruments require arduous disassembly andreassembly procedures that require extensive training, and maydiscourage use of the instrument.

SUMMARY

The present disclosure describes a surgical instrument for treatingtissue. The surgical instrument includes a reusable component and adisposable component selectively separable from and engagable with thereusable component. The disposable component includes an end effectorand a mechanical actuator operable to induce mechanical movement of theend effector. The reusable component is configured for providingelectrosurgical energy to the disposable component when engaged with thedisposable component. A physical mating feature is configured tomaintain engagement between the reusable and disposable components whenthe reusable and disposable components are engaged, and an electricalmating feature is configured to transmit electrical energy between thedisposable and reusable components when the disposable and reusablecomponents are engaged. All mechanical motion resulting from operationof the mechanical actuator may be contained within the disposablecomponent. By appropriately partitioning the instrument betweenrelatively expensive electronic components and relatively inexpensivemechanical components, the cost per use of the instrument may bemanaged.

In one aspect of the present invention, the physical mating featureincludes a pair of contoured guide arms disposed on the reusablecomponent shaped to correspondingly mate with a pair of lateralindentations disposed on the disposable component. The contoured guidearms may include a plurality of bosses disposed on an interior surfacethereof that are positioned to mate with corresponding cavities definedwithin the lateral indentations of the disposable component.

In another aspect of the present disclosure, the physical matingfeatures on the reusable and disposable components may include lip andspring-loaded pin arrangements, tab and insert pins, screw or keyfeatures, magnetic and ferromagnetic components, adhesives or the like.The electrical mating feature may include a plurality of pins thatextend from the reusable component that mate with a correspondingplurality of sockets defined in the housing of the disposable component.A contact guide may be disposed the reusable or disposable component andbe configured to facilitate alignment and engagement of the plurality ofpins and corresponding plurality of sockets.

In another aspect of the present disclosure, the electrical matingfeature may include one or more spring contacts, ring or spade terminalsand blade connectors disposed on the reusable and disposable componentsthat are configured to provide electrical communication betweencomponents once engaged. A key-like interface may be utilized tomaintain mechanical and/or electrical engagement between the reusableand disposable components during use thereof. The key-like interface maybe configured to provide indication to one of the reusable or disposablecomponents that the reusable and disposable components are properlyengaged. Proper engagement therebetween may be a pre-requisite forinitiation of electrical energy and a generator (or a control moduleassociated with the generator) may be dependent upon this feedback as asafety precaution.

In yet another aspect of the present disclosure, the reusable componentis configured to electrically and mechanically connect to anelectrosurgical energy source through a cable connector having one ormore prongs and a terminal array. The terminal array is configured tocouple electrical signal transmission pathways associated with thereusable component to the electrosurgical energy source.

The present disclosure also relates to a surgical instrument including adisposable component having an end effector and a mechanical actuatordisposed thereon, the mechanical actuator operable to induce mechanicalmovement of the end effector. A reusable component is included that isselectively separable from and engagable with the disposable componentand includes an electrical switch disposed thereon configured to allowselective application of electrosurgical energy to the end effector whenthe reusable component is engaged with the disposable component. One ormore physical mating features and one or more electrical mating featuresare provided on the reusable component each configured to engage thedisposable component to maintain mechanical and electrical engagementtherewith.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the presentdisclosure and, together with the detailed description of theembodiments given below, serve to explain the principles of thedisclosure.

FIG. 1 is a right side view of a surgical instrument in accordance withan embodiment of the present disclosure with reusable and disposablecomponents separated;

FIG. 2 is a right side view of the instrument of FIG. 1 with thecomponents assembled;

FIG. 3 is a partial, distally facing perspective view of the instrumentof FIG. 1 with components separated, depicting electrical and physicalmating features of the reusable component;

FIG. 4 is a partial, proximally facing perspective view of theinstrument of FIG. 1 with components separated, depicting electrical andphysical mating features of the disposable component;

FIG. 5 is a partial, perspective view of an alternate embodiment of asurgical instrument including a key lock physical mating feature; and

FIG. 6 is a right side view of an alternate embodiment of a reusablecomponent of a surgical instrument depicting an electrical cable forcoupling the reusable component to a source of electrosurgical energy.

DETAILED DESCRIPTION

Referring initially to FIGS. 1 and 2, an embodiment of anelectrosurgical instrument 10 includes a reusable component 12 and adisposable component 14. The reusable component 12 and the disposablecomponent 14 are selectively engagable with one another (FIG. 2) for usein a surgical procedure, and selectively removable from one another(FIG. 1) for disposal and/or refurbishment of the components 12, 14. Theinstrument 10 includes a handle assembly 22 at a proximal end thereoffor remotely controlling an end effector 24 through an elongated shaft26. Although this configuration is typically associated with instrumentsfor use in laparoscopic or endoscopic surgical procedures, variousaspects of the present disclosure are applicable to traditional openinstruments, and in connection with endoluminal procedures as well.

The reusable component 12 of the instrument 10 includes a source ofelectrosurgical energy, e.g., an electrosurgical generator 28. When thereusable component 12 is coupled to the disposable component 14, thegenerator 28 selectively supplies electrosurgical energy to the endeffector 24. Generators 28 such as the LIGASURE® Vessel SealingGenerator and the Force Triad® Generator as sold by Covidien of BoulderColo. may be utilized for this purpose. The generator 28, depictedschematically in FIG. 1, may include a battery for supplying power tothe instrument, electronic control mechanisms, electrical switching,cordage and other analog or digital devices. Thus, these relativelycomplex electronic devices required for electrically controlling theinstrument 10 are housed within the reusable component 12, and may beused and reused for multiple surgical procedures.

To control the end effector 14, the handle assembly 12 includes astationary handle 34 disposed on the reusable component 34 and a movablehandle 36 disposed on the disposable component 14. The movable handle 36is pivotable with respect to a housing 38 of the disposable componentand, thus, the movable handle 36 is also pivotable with respect to thestationary handle 34 when the reusable and disposable components 12 and14 are coupled to one another. The movable handle 36 is operativelycoupled to the end effector 14 such that the movable handle 36 may beseparated and approximated relative to the stationary handle 34 torespectively open and close the end effector 24. An elongatedreciprocating drive element (not shown) is coupled to the movable handle36, and reciprocates longitudinally through the elongated shaft 26 inresponse to pivoting of the movable handle 36.

A trigger 40 is also disposed on the disposable component 14, and isoperable to extend and retract a knife (not shown) through the endeffector 24. The trigger 24 is operatively coupled to a proximal end ofa reciprocating knife drive element (not explicitly shown), and theknife is operatively coupled to a distal end of the knife drive element.Thus, the trigger 24 is pivotable relative to the housing 38 tolongitudinally move the knife drive element through the elongated shaft26, and the knife through the end effector 24. Also disposed on thedisposable component 14 is a rotation knob 44. The rotation knob 44 isoperable to rotate the elongated shaft 26 and the end effector 24 abouta longitudinal axis A-A defined by the elongated shaft 26. The movablehandle 36, knife actuation trigger 40 and rotation knob 44 may becollectively described as mechanical actuators since these features allcooperate to impart mechanical movement to the end effector 24. Adetailed description of the use of a movable handle 36, knife actuationtrigger 40 and rotation knob 44 as mechanical actuators may be found inU.S. Pat. No. 7,255,697 to Dycus et al. In other embodiments (not shown)an electronic user interface in operative communication with the endeffector 24 may be provided as a mechanical actuator.

The instrument 10 also includes an electrical actuator to permitelectrical actuation of the instrument 10. The electrical actuator isconfigured as a button or switch 48, and is disposed on a housing 50 ofthe reusable component 12 of the instrument 10. The button 48 is inelectrical communication with the generator 28. When the reusablecomponent 12 and disposable component 14 are assembled, the button 48 isalso in electrical communication with the end effector 24. The button 48is thus operable to initiate and terminate the delivery ofelectrosurgical energy to the end effector 24. Other configurations ortypes of electrical actuators may be provided, such as an electricalswitch disposed on the disposable component 14, a separate footswitch(not shown) or other user-manipulated implement.

After use, the reusable component 12 and button 48 are sterilizable byconventional sterilization techniques, such as autoclaving or gassterilization using ethylene oxide or the like while the disposablecomponent 14 is discarded. In this manner, a surgeon is able to utilizethe same specifically-sized or custom-shaped reusable component 12 formultiple surgical procedures with different disposable components 14.Moreover, a surgeon may opt to interchange disposable components 14during a particular procedure while at the same time utilizing the samereusable component 12. Feedback systems and sensors (not explicitlyshown) may be employed to automatically update the generator 28 (or acontrol module associated with the generator 28) each time a newdisposable component 14 is engaged with the reusable component 12 or thesame disposable component is swapped during a particular surgicalprocedure. Techniques may be employed to insure that the disposablecomponent is not used for a subsequent surgery.

Referring now to FIGS. 3 and 4, electrical and physical mating featurespermit the selective engagement and disengagement of the reusable anddisposable components 12, 14 of the instrument 10. The physical matingfeatures serve to secure and maintain the connection between thereusable and disposable components 12, 14, and the electrical matingfeatures establish an electrical pathway between the two components 12,14.

The physical mating features include a pair of contoured guide arms 54on the reusable component 12 that are shaped to correspond to a pair oflateral indentations 56 on the disposable component 14. The guide arms54 are received into the indentations 56 as the reusable and disposablecomponents 12 and 14 are approximated, and facilitate alignment of thetwo components 12, 14. In one embodiment, a plurality of bosses 58 areprovided on an interior or inner peripheral surface of the guide arms 54that correspond to a plurality of cavities 60 provided in theindentation 56 of disposable component. The bosses 58 snap-fit into thecavities 60 to secure the disposable and reusable components, 14 and 12,to one another.

Other alternative physical or mechanical mating features are alsocontemplated including a lip and spring-loaded pin arrangement, a taband inserted pins, a screw or key (see FIG. 5) that is separate orseparable from reusable and disposable components 12, 14, or magneticand ferromagnetic components may be provided to provide an attractiveforce between the two components 12, 14. Additionally, a cleanableadhesive could be provided on the disposable component 14, and a releasestrip could be removed to expose the adhesive prior to installation ofthe disposable component 14 to the reusable component 12.

The electrical mating features include a pair of pins 66 protruding fromthe housing 50 of reusable component 12 and a pair of correspondingsockets 68 defined in the housing 38 of the disposable component 14.Approximation of the reusable and disposable components 12, 14 effectselectrical contact between the pins 66 and sockets 68 as the bosses 58mechanically engage the cavities 60. A contact guide 70 is provided tofacilitate alignment of the pins 66 with the corresponding sockets 68.

The pins 66 are in electrical communication with the generator 28through the switch 48 (FIG. 1), and the sockets 70 are in electricalcommunication with the end effector 24 (FIG. 1). Thus, the generator 28may provide RF therapeutic electrosurgical energy to the end effector 24when the reusable and disposable components 12, 14 are engaged. Theelectrical mating features may alternatively or additionally includeother types of electrical interfaces such as spring contacts, ring orspade terminals, or blade connectors. Also, any number of electricalmating features may be provided to accommodate any number of electricalsignal transmission pathways between the reusable and disposablecomponents 12, 14. Electrical pathways may be provided to transmitdigital or analog signals, or to provide electrical power to any powereddevices on the instrument disposable component 14. In some embodiments(see, e.g., FIG. 6, and related description below), the electricalpathways may extend to a connector to permit connection of theelectrical pathways to associated electrical equipment (not explicitlyshown).

Other types of energy may also be employed for use with the presentdisclosure, ultrasonic, microwave, optical, etc. As can be appreciated,different pin 66 and socket 70 arrangements, mechanical couplings,additional components and/or different electrical circuitry may beneeded to provide one or more of the aforementioned alternate ordifferent types of energy application to tissue.

In use, the reusable component 12 of the instrument 10 is sterilized byany conventional or appropriate sterilization techniques. Subsequently,the reusable component 12 may be mated with a new and sterile disposablecomponent in a sterile operating field. The instrument 10 may then beemployed in a surgical procedure wherein a surgeon or operator grips thestationary handle 34 (FIG. 2) of the reusable component and maneuversand mechanically operates the end effector 24 with the mechanicalactuators 36, 40, and 44 on the disposable portion 14. The end effector24 may be electrically activated by operating the button 48. At thecompletion of the surgical procedure, the disposable component 14 may beseparated from the reusable component 12 and discarded. The reusableportion may be re-sterilized for subsequent use. The cost per surgicalprocedure may be reduced by use of instrument 10 in this manner.

Referring now to FIG. 5, a an alternate embodiment of a surgicalinstrument 76 includes a reusable component 78 and a disposablecomponent 80, which are engaged with one another in a substantiallysimilar manner as the reusable and disposable components 12, 14described above with reference to FIGS. 1 through 4. Additionally ininstrument 76, a separate key or mechanical interface 82 is provided tocomplete the mechanical connection between the reusable and disposablecomponents 78, 80. As the reusable and disposable components 78, 80 areapproximated, keyholes 84 and 86 defined in the respective components78, 80 are aligned. The key 82 may be inserted through the keyhole 84 inthe reusable component 78 and into the keyhole 86 defined in thedisposable component 80 to maintain the mechanical engagement betweenthe components 78, 80.

The key 82 and keyholes 84, 86 may be associated with electronic sensorsor circuits (not explicitly shown) that provide an indication to thegenerator 28 (or a control module associated with the generator 28) thata proper engagement between the components 78, 80 has been achieved.Sensors may include pressure sensors, proximity sensors, simplecircuits, magnetic or ferromagnetic sensors, or any other type of sensorthat may be utilized to provide feedback to the generator 28 (or acontrol module associated with the generator 28) that a propermechanical or electromechanical connection between the reusable anddisposable components 78, 80 has been achieved. Moreover, the sensors orcircuit may be configured to provide feedback to the generator 28 (or acontrol module associated with the generator 28) during anelectrosurgical procedure or provide a feedback test to ensure properconnection between components 78, 80 prior to activation.

Referring now to FIG. 6, an alternate embodiment of reusable component84 includes a housing 86 defining a stationary handle 86 a and guidearms 88. A hook 90 is provided in the housing 86 and may serve as aphysical mating feature for engaging a lip (e.g., lip 120, see FIG. 5)in a disposable component, e.g., 14. Extending from the housing 86, acable 92 provides a mechanism for electrically connecting the reusablecomponent 84 to an external electrosurgical generator (not shown). Thecable 92 includes a connector 94 for coupling the reusable component 84to opposite terminals of the generator. The connector 94 includes twoprong members 94 a and 94 b that are configured to mechanically andelectrically connect the reusable component 84 to opposite terminals,e.g., positive or active (+) and negative or return (−) terminalsassociated with the generator. Thus, bipolar energy may be providedthrough reusable component 84. Alternatively, the reusable component 84may be configured for receiving monopolar energy.

The connector 94 also includes a terminal array 94 c. The terminal array94 c provides a connection mechanism for electrically couplingelectrical signal transmission pathways associated with the reusablecomponent 84 to the external electrosurgical generator (not explicitlyshown). These electrical signal transmission pathways may communicateanalog and/or digital signals between the reusable component and theelectrosurgical instrument. In some embodiments, these electrical signaltransmission pathways may extend through the reusable component 84 to anadditional terminal array (not explicitly shown) that is adapted andarranged to electrically connect the signal transmission pathways to adisposable component whenever the hook 90 is engaged with a disposablecomponent as described above.

In some embodiments, the reusable component 12 (or generator 28) and thedisposable component 14 may be configured to recognize or identify oneanother and provide information relating to energy parameters, or thetype of surgical procedure that is involved, e.g., monopolar, bipolar,ultrasonic, etc. Examples, of such reusable logic may include bar codes,Aztec Codes, optical codes and the like.

Although the foregoing disclosure has been described in some detail byway of illustration and example, for purposes of clarity orunderstanding, it will be obvious that certain changes and modificationsmay be practiced within the scope of the appended claims.

What is claimed is:
 1. A surgical instrument, comprising: a disposablecomponent including an end effector and a mechanical actuator disposedthereon, the mechanical actuator operable to induce mechanical movementof the end effector; a reusable component selectively separable from andengagable with the disposable component, the reusable componentconfigured for providing electrosurgical energy to the disposablecomponent when engaged with the disposable component; a physical matingfeature provided on at least one of the disposable and reusablecomponents, the physical mating feature configured to maintainengagement between the reusable and disposable components when thereusable and disposable components are engaged; an electrical matingfeature provided on the disposable and reusable components configured totransmit electrical energy between the disposable and reusablecomponents when the disposable and reusable components are engaged; anda keyhole formed in each of the disposable and reusable components, thekeyholes configured for receipt of a key-like interface to maintain atleast one of mechanical or electrical engagement of the reusable anddisposable components during use thereof.
 2. The surgical instrumentaccording to claim 1, wherein the key-like interface is configured toprovide indication to one of the reusable or disposable components thatthere is proper engagement therebetween.
 3. The surgical instrumentaccording to claim 1, wherein all mechanical motion resulting fromoperation of the mechanical actuator is contained within the disposablecomponent.
 4. The surgical instrument according to claim 1, wherein thephysical mating feature includes a pair of contoured guide armsextending distally from the reusable component, the pair of contouredguide arms shaped to correspondingly mate with a pair of lateralindentations formed in an outer surface of the disposable component. 5.The surgical instrument according to claim 4, wherein each of the pairof contoured guide arms includes at least one boss extending inwardlyfrom an interior surface thereof that are positioned to mate withcorresponding cavities defined within the pair of lateral indentationsof the disposable component.
 6. The surgical instrument according toclaim 1, wherein the physical mating feature includes at least one oflip and spring-loaded pin arrangements, tab and insert pins, screw orkey features, magnetic and ferromagnetic components, or adhesives. 7.The surgical instrument according to claim 1, wherein the electricalmating feature includes a plurality of pins that extend from an interiorsurface of the reusable component that mate with a correspondingplurality of sockets defined in the housing of the disposable component.8. The surgical instrument according to claim 7, further comprising acontact guide disposed on one of the reusable or disposable componentsand configured to facilitate alignment and engagement of the pluralityof pins and corresponding plurality of sockets.
 9. The surgicalinstrument according to claim 1, wherein the reusable component furtherincludes a cable, the cable having a cable connector configured toelectrically and mechanically connect to an electrosurgical energysource, the cable connector having one or more prongs and a terminalarray, the terminal array being configured to couple electrical signaltransmission pathways associated with the reusable component to theelectrosurgical energy source.
 10. A surgical instrument, comprising: adisposable component including; a housing; a mechanical actuatorpivotably connected to the housing; an elongated shaft extendingdistally from the housing; and an end effector connected to theelongated shaft, wherein the mechanical actuator operably inducesmechanical movement of the end effector; a reusable component including:a housing; and a stationary handle extending from the housing of thereusable component, wherein the housing of the reusable component isselectively separable from and engagable with the housing of thedisposable component, the housing of the reusable component including anelectrical switch disposed thereon and configured to allow selectiveapplication of electrosurgical energy to the end effector when thereusable component is engaged with the disposable component; at leastone physical mating feature and at least one electrical mating featureprovided on the housing of the reusable component each configured toengage the housing of the disposable component to maintain mechanicaland electrical engagement therewith, wherein the physical mating featureincludes a pair of contoured guide arms extending distally from thehousing of the reusable component shaped to correspondingly mate with apair of lateral indentations formed in an outer surface of the housingof the disposable component.
 11. The surgical instrument according toclaim 10, wherein each of the pair of contoured guide arms includes atleast one boss extending inwardly from an interior surface thereof thatis positioned to mate with corresponding cavities defined within thepair of lateral indentations of the housing of the disposable component.12. The surgical instrument according to claim 10, wherein thedisposable component further includes a knob rotatably connected to thehousing of the disposable component.
 13. The surgical instrumentaccording to claim 10, wherein the mechanical actuator of the disposablecomponent is a movable handle.
 14. The surgical instrument according toclaim 10, wherein the disposable component further includes a triggerpivotably connected to the housing of the disposable component.
 15. Asurgical instrument, comprising: a disposable component including: ahousing having a proximal end; a mechanical actuator pivotably connectedto the housing; an elongated shaft extending distally from the housing;and an end effector connected to the elongated shaft, wherein themechanical actuator operably induces mechanical movement of the endeffector; a reusable component including: a housing defining a cavitytherein configured for receipt of the proximal end of the housing of thedisposable component; and a stationary handle extending from the housingof the reusable component, wherein the housing of the reusable componentis selectively separable from and engagable with the housing of thedisposable component, the housing of the reusable component including anelectrical switch disposed thereon and configured to allow selectiveapplication of electrosurgical energy to the end effector when thereusable component is engaged with the disposable component; and atleast one physical mating feature and at least one electrical matingfeature provided on the housing of the reusable component eachconfigured to engage the housing of the disposable component to maintainmechanical and electrical engagement therewith, wherein the at least onephysical mating feature includes at least one of lip and spring-loadedpin arrangements, tab and insert pins, screw or key features, magneticand ferromagnetic components, or adhesives.
 16. The surgical instrumentaccording to claim 15, wherein the at least one electrical matingfeature includes a plurality of pins that extend from an interiorsurface of the housing of the reusable component that mate with acorresponding plurality of sockets defined in the housing of thedisposable component.
 17. The surgical instrument according to claim 16,further comprising a contact guide disposed on one of the housings ofthe reusable or disposable components and configured to facilitatealignment and engagement of the plurality of pins and correspondingplurality of sockets.
 18. The surgical instrument according to claim 15,further comprising a a keyhole formed in each of the housings of thedisposable and reusable components, the keyholes configured for receiptof a key-like interface to maintain at least one of mechanical orelectrical engagement of the reusable and disposable components duringuse thereof.
 19. The surgical instrument according to claim 18, whereinthe key-like interface is configured to provide indication to a controlmodule that the reusable and disposable components are properly engaged.